Abstract：
In emergencies like the COVID-19 pandemic, the reuse or reprocessing of filtering facepiece respirators (FFRs) may be required to mitigate exposure risk. Research gap: Only a few studies evaluated decontamination effectiveness against SARS-CoV-2 that are practical for low-resource settings. This study aimed to determine the effectiveness of a relatively inexpensive ultraviolet germicidal irradiation chamber to decontaminate FFRs contaminated with SARS-CoV-2. A custom-designed UVGI chamber was constructed to determine the ability to decontaminate seven FFR models including N95s, KN95, and FFP2s inoculated with SARS-CoV-2. Vflex was excluded due to design folds/pleats and UVGI shadowing inside the chamber. Structural and functional integrity tolerated by each FFR model on repeated decontamination cycles was assessed. Twenty-seven participants were fit-tested over 30 cycles for each model and passed if the fit factor was ≥100. Of the FFR models included for testing, only the KN95 model failed filtration. The 3M™ 3M 1860 and Halyard™ duckbill 46727 (formerly Kimberly Clark) models performed better on fit testing than other models for both pre-and-post decontaminations. Fewer participants (0.3 and 0.7%, respectively) passed fit testing for Makrite 9500 N95 and Greenline 5200 FFP2 and only two for the KN95 model post decontamination. Fit testing appeared to be more affected by donning & doffing, as some passed with adjustment and repeat fit testing. A ≥ 3 log reduction of SARS-CoV-2 was achieved for worn-in FFRs namely Greenline 5200 FFP2. Conclusion: The study showed that not all FFRs tested could withstand 30 cycles of UVGI decontamination without diminishing filtration efficiency or facial fit. In addition, SARS-CoV-2 log reduction varied across the FFRs, implying that the decontamination efficacy largely depends on the decontamination protocol and selection of FFRs. We demonstrated the effectiveness of a low-cost and scalable decontamination method for SARS-CoV-2 and the effect on fit testing using people instead of manikins. It is recognized that extensive experimental evidence for the reuse of decontaminated FFRs is lacking, and thus this study would be relevant and of interest in crisis-capacity settings, particularly in low-resource facilities.
摘要：
在像COVID-19大流行这样的紧急情况下，可能需要重复使用或再处理过滤面罩呼吸器（FFR）以减轻暴露风险。研究差距：只有少数研究评估了对低资源环境实用的SARS-CoV-2的净化效果。这项研究旨在确定相对便宜的紫外线杀菌照射室对受SARS-CoV-2污染的FFRs的净化效果。构建了定制设计的UVGI腔室，以确定对包括N95在内的七种FFR模型进行净化的能力，KN95和接种SARS-CoV-2的FFP2。由于腔室内的设计折叠/褶皱和UVGI阴影，排除了Vflex。评估每个FFR模型在重复净化循环中耐受的结构和功能完整性。对于每个模型，27名参与者在30个周期内进行了拟合测试，如果拟合因子≥100，则通过了测试。在用于测试的FFR模型中，只有KN95型号过滤失败。3M™3M1860和Halyard™鸭嘴46727（以前称为KimberlyClark）模型在配合测试中的性能优于其他模型，用于净化前后。更少的参与者(0.3%和0.7%，分别）通过了Makrite9500N95和Greenline5200FFP2的拟合测试，仅通过了KN95模型净化后的拟合测试。合身测试似乎受到穿戴和脱毛的影响更大，如一些通过调整和重复拟合测试。对于磨损的FFR，即Greenline5200FFP2，SARS-CoV-2的对数减少≥3。结论：研究表明，并非所有测试的FFR都可以承受30次UVGI净化循环，而不会降低过滤效率或面部贴合性。此外,SARS-CoV-2对数减少在FFR中有所不同，这意味着净化效果在很大程度上取决于净化方案和FFR的选择。我们证明了一种低成本且可扩展的SARS-CoV-2净化方法的有效性，以及使用人代替人体模型对拟合测试的影响。人们认识到，缺乏重复使用去污FFRs的广泛实验证据，因此，这项研究将是相关的，并对危机能力设置感兴趣，特别是在低资源设施中。
